She does as directed, and the priest’s wounds flow scarlessly closed. 

There is a celebration of the tides tonight, in which the majority of the flock will be in attendance. Those whose duties as city watch wouldn’t make their absence notable. 

They also intend to sacrifice a slave via drowning. The priest speaks about this at length and with great anticipation.  

"Oh, how wonderful! A sacrifice! Who is the slave, someone worthy?"

Just some half-elvish healer without any meaningful power. Her mother was supposedly taken from Dath Lomin itself, and her father was a sailor aboard the Shell Islander slaver’s galley that captured the mother. This is why the daughter was selected for sacrifice: an eternal life sacrificed is a greater gift than a mortal one, and someone conceived aboard a ship is a fitting sacrifice to the lord of the deeps. 

"Oh my! What an amateur mistake! Perhaps I could have expected no better of one who would renounce his god over a little pain. No, the worthiest sacrifices are obviously those that have the most faith. Now who in your little congregation has the most faith, do you think? No, don't look so concerned. It couldn't be you. You renounced your god, you are nothing to it now."

“…” the priest says. He rubs at his now-healed wounds. “That would be the Speaker for the Sacrament of Drowning…. Err… he gives the lesson while I…” he glances at the basin. 

"Hm. I'm not sure I trust your assessment of his character. I would have figured you were worthy, after all. Who's to say he'll do any better. We should check. Take us to him."

“He is in the storage room with the slave… ought I to call him, or… I’ll take you to him I suppose.” 

The storage room is larger than the priest’s quarters, but not by much. Mouldering crates lie all about, as well as a not-quite-large-enough rust-reddened cage. A bound, gagged, and blindfolded half-elven girl trembles within. A large man in the same profaned ocher robes sits on a crate nearby, scarred hands whittling away, a small mountain of wood shavings about his feet. 

"He has potential, but he'll need to be tested. Explain the issue to him."

The priest explains with that deep compelling orrator’s voice- about how the Doom requires a worthier sacrifice than a slave, about the speaker’s peerless dedication. 

The speaker stands proudly. “I would be honored to serve,” he bows his head. 

“Right,” the girl hefts her preternaturally keen sword. “One butchery, coming right up.” 

“Ah,” the speaker smiles. “Beautiful child… I see our lord of madness has already touched the princess’s mind. Truly our victory is assured.” 

“Oh she’s crazy,” the girl snarls “Oh she’s… shut up about the crazy! Everyone knows I’m the princess with the broken brain. It’s not news anymore! Well she’s not a princess anymore, and she’s tired of hearing how crazy she is!”

The girl rams her blade through the man’s shoulder, pins him to the crate behind. “Voice?” She says. “Hurt him.” 

The voice will oblige.

The speaker suffers a truly astonishing amount of pain before recanting, but their faith is about madness and death. Agony eventually breaks it. 

"No, priest, you seem to have been wrong. This one was not worthy. Speaker, you have a chance to redeem yourself. Who here is more loyal than you? Find them for us."

The speaker is not yet verbal, gasping and panting long after his wounds are closed. 

The priest glances at the ruin of his speaker, bites his lip. “What? Um… the acolyte of the abyss, I would suppose?” 

They can give him a moment, but the voice doesn't have much regard for the feelings of wayward cultists.

"An acolyte? We shall see."

She is a short, reedy little acolyte in stained ocher robes. One could be forgiven for assuming she has gnomish or halfling blood somewhere in her ancestry, but otherwise unremarkable features. 

“Priest,” she bows as she enters. “Speaker,” she bows somewhat less deeply. “How may your humble servant assist you?” 

"We seek one who is worthy. Are you worthy, child?"

“Probably not,” the acolyte replies, “but I am willing to try. What must I do?” 

"Your god is one of madness and oblivion. We must test your limits, and see where your faith falls between those lines. Priest, you should take responsibility for this search."

The priest takes some convincing, but not as much as might be expected. Certainly he is more comfortable dealing pain than receiving it, and is as enthusiastic about drowning others as he was horrified of drowning himself. 

The acolyte breaks quickly. 

"Disappointing. We may need to be more efficient. Call the flock together for the sacrifice, we shall proceed when we have more candidates available."

The flock is called- those who are present, that is. The commotion in the store above prevents summoning those members who are not currently within the cave complex.